1. Field of the Invention
The present invention relates to an image sensor, and more particularly, it relates to an image sensor comprising an imaging element.
2. Description of the Background Art
An image sensor comprising an imaging element is known in general, as disclosed in each of Japanese Patent Laying-Open Nos. 2007-128016, 2007-025180, 2000-307937, 2001-264840 and 2006-343698, for example.
The aforementioned Japanese Patent Laying-Open No. 2007-128016 discloses a corrector comprising a CCD (imaging element), an X stage (movable member) for mounting the CCD, a driving source (driving source) having a rotating shaft provided with a screw portion for moving the X stage, a nut (pressing member) having a screw portion and a spring member parallelly mounted on the rotating shaft for urging the X stage. This corrector is so formed that the screw portion of the rotating shaft of the driving source and the screw portion of the nut engage with each other. Further, the corrector is so formed that the X stage moves in a first direction while a Y stage moves in a second direction orthogonal to the first direction. In addition, the corrector is so formed that the X stage moves in the second direction following the movement of the Y stage in the second direction.
The aforementioned Japanese Patent Laying-Open No. 2007-025180 discloses a stage unit comprising an imaging element, a storing/holding portion (movable member) for storing the imaging element, a plate spring (spring member) mounted on a frame of the storing/holding portion for moving the storing/holding portion, a coil (driving source) for generating driving force and a magnetic force generator for generating magnetic force. This stage unit is so formed as to generate the driving force in the coil by the magnetic force generated in the magnetic force generator and deflecting the plate spring thereby moving the storing/holding portion in a first direction and a second direction orthogonal to the first direction.
The aforementioned Japanese Patent Laying-Open No. 2000-307937 discloses an image sensor comprising an imaging element, a substrate (movable member) for mounting the imaging element, a piezoelectric element (driving source) for generating driving force and a plate spring (spring member) mounted on the piezoelectric element to be parallel to the substrate for coming into contact with the substrate. This image sensor is so formed as to deflect the plate spring by expanding/contracting the piezoelectric element thereby moving the substrate mounted with the imaging element in a first direction and a second direction orthogonal to the first direction.
The aforementioned Japanese Patent Laying-Open No. 2001-264840 discloses an optical device comprising a correction lens serving also as an imaging element, a support frame (movable member) for supporting the correction lens, a base plate for mounting the support frame, a yoke for generating magnetic force, a coil (driving source) for generating driving force and a spring member for regulating movement. In this optical device, the support frame is arranged in the base plate, while the support frame and the base plate are coupled with each other by the spring member. Movement of the support frame is regulated by the spring member in the base plate. The yoke is mounted on the support frame, and the optical device is so formed as to move the support frame in a first direction and a second direction orthogonal to the first direction due to the driving force generated in the coil.
The aforementioned Japanese Patent Laying-Open No. 2006-343698 discloses an image sensor comprising an imaging unit mounted with an imaging element, a frame (movable member) for mounting the imaging unit, an actuator (driving source) having a drive shaft (pressing member) and a spring member. This image sensor is so formed as to move the frame in a first direction and a second direction orthogonal to the first direction by driving the drive shaft of the actuator. The spring member is mounted on the drive shaft, to urge the frame.
In the corrector according to the aforementioned Japanese Patent Laying-Open No. 2007-128016 in which the screw portions of the rotating shaft of the driving source and the nut engage with each other, however, a backlash (clearance) is generally present between the screw portions. Further, the urging direction of the spring member changes when the X stage moving in the first direction moves in the second direction orthogonal to the first direction due to the movement of the Y stage. When the urging direction of the spring member changes, the quantity of movement of the nut may conceivably change by the backlash between the screw portions of the rotating shaft and the nut. In this case, therefore, the quantity of movement of the imaging element may disadvantageously change.
In the stage unit according to the aforementioned Japanese Patent Laying-Open No. 2007-025180, the plate spring is so deflected as to move the storing/holding portion, and hence the urging direction of the spring in the first direction may conceivably change when the storing/holding portion is moved in the second direction. When the urging direction of the plate spring changes, the quantity of movement of the storing/holding portion may conceivably change. In this case, therefore, the quantity of movement of the imaging element may disadvantageously change.
In the image sensor according to the aforementioned Japanese Patent Laying-Open No. 2000-307937, the plate spring is so deflected as to move the substrate, and hence the urging direction of the plate spring in the first direction may conceivably change when the substrate is moved in the second direction. When the urging direction of the plate spring changes, the quantity of movement of the substrate (imaging element) may disadvantageously change.
In the optical device according to the aforementioned Japanese Patent Laying-Open No. 2001-264840, the urging direction of the spring member in the first direction may conceivably change when the support frame is moved in the second direction. When the urging direction of the spring member changes, the quantity of movement of the support frame (imaging element) may disadvantageously change.
In the image sensor according to the aforementioned Japanese Patent Laying-Open No. 2006-343698, the urging direction of the spring member in the first direction may conceivably change when the imaging unit is moved in the second direction. When the urging direction of the spring member changes, the quantity of movement of the imaging unit (imaging element) may disadvantageously change.